To ask about trimethoprim dosage

[Midlandsmummy29]

Just back from out of hours with 3 year old DD who has a UTI. Prescribed 10ml dosage of trimethoprim twice daily. Gave first dosage and then read the leaflet- it advises 5ml twice daily for 6 months - 5 years. Now freaking out slightly that out of hours have given me the wrong dosage?!

Has anyone been prescribed higher dosages of this? I know I should call NHS 24 for advice but I’ll be on hold for a while....

I would probably call 111 to be in the safe side I have been given very strong antibiotics for a UTI but not as a child

Looking at the BNFc dose is 50mg twice daily or 4mg/kg twice daily with a max per dose of 200mg.
I think most trimethoprim comes as 50mg in 5ml which would suggest it should be 5mls twice daily for the 50mg dose and up to 20 mls for the 200mg dose.
Do you know much your daughter weighs?

I’m actually on these at the moment !
Is your daughter taller than average ? I have a very tall daughter so always got higher dosages .
Even for calpol / nurofen , it’s calculated by weight instead of age .

My daughter weighs about 14kg, she’s petite. From looking at it, they’ve prescribed her the dosage for 6-12 year olds.

It does seem they've done the higher dose.
At 14kg a top dose at 4mg/kg is 56mg which would be 5.6mls twice a day.

Does your bottle say it's 50mg/5ml?

Yes 50mg/5ml.

It seemed high but we were keen to get the first dose in and get DD settled again. Then I read the label. Looked on NHS website and it said that giving a second dose “by accident” should not cause any harm, just be aware of sickness etc.

I’ll keep an eye on her overnight and phone NHS 24 in the morning- think it really should be 5 ml doses, it’s not a severe infection.

It's usually 5ml. Give nhs24 a call they can advise on taking too much but sure she will be fine. Glad you noticed!